A run-time call stack can be used during execution of a program written in a programming language. The program can include, for example, an initial control flow, and other, internal control flows that are internal to, or nested within, the initial control flow. Each internal control flow can include one or more other internal control flows. That is, the initial control flow and an internal control flow can each call one or more other internal control flows. When an internal control flow is called, a memory stack frame associated with the internal control flow can be added to (e.g., “pushed onto”) the run-time call stack. The memory stack frame can be used, for example, to store parameter information that is passed between the calling control flow and the called control flow. The memory stack frame can also be used to store local variables used within the called control flow. When execution of the called internal control flow completes, the memory stack frame associated with the called internal control flow can be removed from (e.g., “popped off”) the run-time call stack.